Bottom Line:
Similarly, although decoding accuracies surpassed the chance level in both real and imagined movements, these were significantly different after the onset.The temporal correlation of decoding accuracy significantly increased around the hand and arm areas, except for the period immediately after response onset.Our results suggest that cM1 is involved in similar neural activities related to the representation of motor information during real and imagined movements, except for presence or absence of sensory-motor integration induced by sensory feedback.

ABSTRACTThe relationship between M1 activity representing motor information in real and imagined movements have not been investigated with high spatiotemporal resolution using non-invasive measurements. We examined the similarities and differences in M1 activity during real and imagined movements. Ten subjects performed or imagined three types of right upper limb movements. To infer the movement type, we used 40 virtual channels in the M1 contralateral to the movement side (cM1) using a beamforming approach. For both real and imagined movements, cM1 activities increased around response onset, after which their intensities were significantly different. Similarly, although decoding accuracies surpassed the chance level in both real and imagined movements, these were significantly different after the onset. Single virtual channel-based analysis showed that decoding accuracy significantly increased around the hand and arm areas during real and imagined movements and that these are spatially correlated. The temporal correlation of decoding accuracy significantly increased around the hand and arm areas, except for the period immediately after response onset. Our results suggest that cM1 is involved in similar neural activities related to the representation of motor information during real and imagined movements, except for presence or absence of sensory-motor integration induced by sensory feedback.

f5: Temporal correlation of decoding accuracy between real and imagined movements.Each plot depicts the correlation coefficients averaged over subjects at each time window. Temporal correlation began to increase significantly from −200 ms (from −450 to 50 ms) around the medial part of cM1, particularly around the hand and arm areas. These significant correlations disappeared around response onset and reappeared from 400 ms (150–650 ms). Correlation coefficients at p < 0.05 were considered statistically significant and were plotted (Spearman’s rank correlation test, p < 0.05, false discovery rate-corrected).

Mentions:
The temporal correlation of decoding accuracy between real and imagined movements was also examined in each virtual channel. Figure 5 shows temporal correlations of particular time ranges of decoding accuracy in cM1 between real and imagined movements. The temporal correlation significantly increased from −200 ms (−450–50 ms) around the medial part of cM1, including the hand and arm areas [Spearman’s rank correlation test, p < 0.05, false discovery rate (FDR)-corrected] (Fig. 5, also see Fig. 6B). Although this significant correlation disappeared around response onset, it reappeared from 400 ms (150–650 ms) (Fig. 5 and Supplementary movie 5). Temporal correlations were also calculated in the other seven ROIs. The results showed a significant correlation between cS1 before and after response onset but not from 100 to 300 ms, which was weaker than that in cM1 (Fig. S9) (Spearman’s rank correlation test, p < 0.05, FDR-corrected). These significant correlations tended to cluster around the hand and arm areas. The remaining six ROIs showed no significant temporal correlation.

f5: Temporal correlation of decoding accuracy between real and imagined movements.Each plot depicts the correlation coefficients averaged over subjects at each time window. Temporal correlation began to increase significantly from −200 ms (from −450 to 50 ms) around the medial part of cM1, particularly around the hand and arm areas. These significant correlations disappeared around response onset and reappeared from 400 ms (150–650 ms). Correlation coefficients at p < 0.05 were considered statistically significant and were plotted (Spearman’s rank correlation test, p < 0.05, false discovery rate-corrected).

Mentions:
The temporal correlation of decoding accuracy between real and imagined movements was also examined in each virtual channel. Figure 5 shows temporal correlations of particular time ranges of decoding accuracy in cM1 between real and imagined movements. The temporal correlation significantly increased from −200 ms (−450–50 ms) around the medial part of cM1, including the hand and arm areas [Spearman’s rank correlation test, p < 0.05, false discovery rate (FDR)-corrected] (Fig. 5, also see Fig. 6B). Although this significant correlation disappeared around response onset, it reappeared from 400 ms (150–650 ms) (Fig. 5 and Supplementary movie 5). Temporal correlations were also calculated in the other seven ROIs. The results showed a significant correlation between cS1 before and after response onset but not from 100 to 300 ms, which was weaker than that in cM1 (Fig. S9) (Spearman’s rank correlation test, p < 0.05, FDR-corrected). These significant correlations tended to cluster around the hand and arm areas. The remaining six ROIs showed no significant temporal correlation.

Bottom Line:
Similarly, although decoding accuracies surpassed the chance level in both real and imagined movements, these were significantly different after the onset.The temporal correlation of decoding accuracy significantly increased around the hand and arm areas, except for the period immediately after response onset.Our results suggest that cM1 is involved in similar neural activities related to the representation of motor information during real and imagined movements, except for presence or absence of sensory-motor integration induced by sensory feedback.

ABSTRACTThe relationship between M1 activity representing motor information in real and imagined movements have not been investigated with high spatiotemporal resolution using non-invasive measurements. We examined the similarities and differences in M1 activity during real and imagined movements. Ten subjects performed or imagined three types of right upper limb movements. To infer the movement type, we used 40 virtual channels in the M1 contralateral to the movement side (cM1) using a beamforming approach. For both real and imagined movements, cM1 activities increased around response onset, after which their intensities were significantly different. Similarly, although decoding accuracies surpassed the chance level in both real and imagined movements, these were significantly different after the onset. Single virtual channel-based analysis showed that decoding accuracy significantly increased around the hand and arm areas during real and imagined movements and that these are spatially correlated. The temporal correlation of decoding accuracy significantly increased around the hand and arm areas, except for the period immediately after response onset. Our results suggest that cM1 is involved in similar neural activities related to the representation of motor information during real and imagined movements, except for presence or absence of sensory-motor integration induced by sensory feedback.